Interfolder and Separator Arrangement and Methods of Separating a Stack of Sheets From a Continuously Building Stream of Sheets

ABSTRACT

Methods and apparatuses for separating streams of interfolded sheets into individual stacks of sheets are provided. Separation of the stacks is provided by a plurality of fingers mounted to carriages that are moved into and out of openings the stream of interfolded sheets. The openings may be formed without using the force of gravity. Further, the fingers may be inserted into the openings with a motion that has a larger component in a direction parallel to the stream of interfolded sheets than in a direction perpendicular to the stream of interfolded sheets. Further, the components that separate the stacks also may transport the stacks and directly transfer the stacks to downstream components.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims the benefit of U.S. Provisional Patent Application No. 62/056,084, filed Sep. 26, 2014, the entire teachings and disclosure of which are incorporated herein by reference thereto.

FIELD OF THE INVENTION

This invention relates to a method and apparatus for separating a stack of folded articles, such as paper towels, napkins, facial tissues or the like, into stacks having a desired number of folded articles.

BACKGROUND OF THE INVENTION

There are many products, as exemplified by paper tissue, toweling and napkins, etc., which are commonly provided to consumers in stacked form as packs of folded or interfolded individual sheets. These packs of stacked sheets are often staple items which must be produced at very low cost. Producing such products at low cost typically requires the use of high-speed processes and equipment. Such processes are not limited to the production and delivery of paper products, but are widely used in the production of other products such as foil, textile, synthetic sheeting and other industries.

Such products are often formed from one or more continuous webs of materials or from one or more streams of sheets which are folded in a folding apparatus into the desired configuration and deposited in a stacking region extending downstream from the folding apparatus. The stack of sheets in the stacking region is then periodically separated into packs having a desired number of sheets.

Experience has shown that the steps of cutting individual sheets from a web or webs of material, and folding or interfolding the individual sheets to form a stack of folded sheets can be accomplished at higher speeds than subsequent downstream processes such as: separating a stack of the folded material into individual packs having a desired number of sheets; performing secondary folding of a lead or trailing sheet of each pack; and delivering the completed pack to downstream packaging equipment used to wrap or otherwise prepare the completed packs for delivery and sale.

In the past, a variety of approaches have been utilized for: separating stacks of folded sheets, and particularly interfolded sheets, into packs; performing any necessary secondary folding operations; and transporting the completed packs to downstream processing equipment. Some of these prior approaches are illustrated in the following US patents which are commonly assigned to the assignee of the present invention: U.S. Pat. No. 4,770,402 to Couturier; U.S. Pat. No. 4,874,158 to Retzloff; U.S. Pat. No. 6,641,358 to Schmidt et al.; U.S. Pat. No. 6,322,315 to Schmidt et al; U.S. Pat. No. 8,240,653 to Walsh et al.; and U.S. Pat. No. 8,333,370 to Walsh.

Although the apparatuses and methods taught by Couturier and in other prior approaches as exemplified by the US patents listed above have been successful and commercially viable in the past, further improvement is desirable. Specifically, it is desirable to provide a separation method and apparatus which is operable at higher speeds than can be achieved using prior approaches. Also, it is desirable to provide improved separation methods and apparatuses having a more straightforward construction and operation, ideally having fewer components, which can be produced and operated at lower cost and with higher efficiency and reliability.

Prior separating methods and apparatuses have also generally been limited to use with folded sheets issuing along a substantially vertically oriented folded sheet path to form a stack in which the successive sheets rest vertically upon one another. Many vertically oriented separating methods and apparatuses have relied, at least in some parts, on gravity for creating spaces for insertion of separating devices. When relying on gravity, due to the inconsistencies in the material, environmental temperature/humidity and product folding and interfolding, the spaces may not form consistently such that the spaces are not always formed in the proper spots.

Most separating methods and apparatuses use count fingers for separating individual stacks of sheets from the continuous stream of interfolded sheets coming from counter-rotating folding rolls. Unfortunately, under increased speed requirements as well as an increased desired for stack uniformity and appearance, current count finger design and configuration provides undesirable looking and shaped stacks of sheets.

The present invention provides improvements over the current state of the art of separators for separating stacks of sheets from a continuous stream of sheets provided by a folder.

SUMMARY OF THE INVENTION

A new and improved separator and method of separating stacks of sheets from a continuous stream of interfolded sheets is provided.

In one embodiment, a method of separating a stack of sheets from a continuous stream of interfolded sheets is provided. The method includes supporting a continuously forming stream of interfolded sheets on a lower carriage; inserting first, second, third and fourth count fingers into separate openings of the stream of interfolded sheets upstream of the lower carriage; supporting a first upstream sheet forming a first bottom sheet of the continuous stream of interfolded sheets with the third count finger and controlling a first downstream sheet forming a top sheet of the stack with the second count finger; increasing the spacing between the third and second count finger to separate the first upstream sheet from the first downstream sheet.

In a particular embodiment, the method includes supporting a second bottom sheet forming a bottom of the stack with the lower carriage and securing the stack of sheets between the lower carriage and the first count finger and second count finger such that the stack of sheets is controlled by the lower carriage and the first count finger and second count finger.

In a particular embodiment, the method includes transporting the stack of sheets to a downstream component under the control of the first count finger, the second count finger and the lower carriage and directly transferring the stack of sheets to the downstream component from the control of the first count finger, second count finger and lower carriage

In a particular embodiment of a method, the downstream component is a conveyor. Transporting the stack of sheets includes directly transferring the stack of sheets to the conveyor from the control of the first count finger, second count finger and the lower carriage.

In a particular embodiment, directly transferring the stack of sheets to the downstream component includes retracting the lower carriage, first count finger and second count finger transversely from a center line defined by the stream of interfolded sheets.

In a particular embodiment, the retraction of the lower carriage, first count finger and second count finger is perpendicular to center line defined by the stream of interfolded sheets.

In a particular embodiment, the method further includes, after transferring the stack of sheets to the downstream component, inserting the lower carriage into the opening in which the third count finger is located and then retracting the third and fourth count fingers to hand off the continuously forming stream of interfolded sheets to the lower carriage.

In a particular embodiment, the method includes separating a second stack of sheets from the stream of interfolded sheets including: inserting first, second, third and fourth count fingers into a second set of separate openings of the stream of interfolded sheets upstream of the lower carriage; supporting a second upstream sheet forming a second bottom sheet of the continuous stream of interfolded sheets with the third count finger and controlling a second downstream sheet forming a top sheet of the second stack of sheets with the second count finger; increasing the spacing between the third and second count finger to separate the second upstream sheet from the second downstream sheet.

In a particular embodiment, the separate openings include first, second, third and fourth openings. The first and second openings are immediately adjacent one another. The third and fourth openings are immediately adjacent one another. The second and third openings are separated from one another by a fifth opening.

In a particular embodiment, inserting first, second, third and fourth count fingers into separate openings of the stream of interfolded sheets upstream of the lower carriage includes: inserting the first, second, third and fourth count fingers into four consecutive openings when adjacent sheets of the continuous stream of interfolded sheets have only a single panel interfolded; and inserting the first and second count fingers into consecutive openings and inserting the third and fourth count fingers into consecutive openings and wherein the second and third count fingers are inserted into openings that are separated from one another by an opening other than the first and fourth openings when adjacent sheets of the continuous stream of interfolded sheets have more than one panel interfolded.

In a particular embodiment, the count fingers are mounted to independently movable carriages.

In a particular embodiment, none of the openings in the continuous stream of interfolded sheets in which components are inserted are formed by gravity.

In a particular embodiment, the method further includes switching the order of insertion of the first count finger and the second count finger such that the first count finger acts as the second count finger but from an opposite side of a center line of the continuous stream of interfolded sheets. The method further includes switching the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line. The method further includes switching the order of insertion of the lower carriage and a sixth carriage such that the sixth carriage acts as the lower carriage but from the opposite side of the center line.

In a particular embodiment, the first count finger, third count finger and lower carriages are located on a same first side of the center line and the second count finger, fourth count finger and sixth carriages are located on same second side of the center line being opposite the first side.

In one embodiment, an apparatus for forming stacks of interfolded sheets from a stream of sheets is provided. The apparatus includes an interfolder arrangement and a separator arrangement. The interfolder arrangement interfolds the stream of sheets into a continuous stream of interfolded sheets. The separator arrangement includes a lower carriage, first, second, third and fourth count fingers and a controller. The lower carriage is downstream from the interfolder arrangement. The lower carriage selectively supports the continuous stream of interfolded sheets exiting the interfolder arrangement. The first, second, third and fourth count fingers are insertable into first, second, third and fourth openings of the continuous stream of interfolded sheets upstream of the lower carriage. The controller is configured to control the motion of the lower carriage, and first, second, third and fourth count fingers into the continuous stream of interfolded sheets. The controller is configured to control the third count finger to be inserted into the third opening formed by a first upstream sheet forming a first bottom sheet of the continuous stream of interfolded sheets to support the first bottom sheet of the continuous stream of interfolded sheets upstream of the lower carriage. The controller is configured to control the second count finger to be inserted into the second opening formed by a first downstream sheet forming a top sheet of the stack to control a top of the stack upstream of the lower carriage. The controller is configured to control the second count finger, third count finger and lower carriage to increase the spacing between the third and second count finger to separate the first upstream sheet from the first downstream sheet.

In a particular embodiment, the separator arrangement is configured to operate in a first count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets have only a single panel interfolded. The separator arrangement is configured to operate in a second count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets have more than one panel interfolded. When operating in the first count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings such that the first, second, third and fourth count openings are consecutive openings. When operating in the second count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings, respectively, with the first and second openings being adjacent one another, the third and fourth openings being adjacent one another and the second and third openings being separated from one another by an opening other than the first, second, third and fourth openings.

In a particular embodiment, the apparatus includes a downstream component downstream from the interfolder arrangement. The separator arrangement transports the stacks of interfolded sheets to the downstream component with the stack being controlled between the lower carriage and the first and second count fingers such that the stacks of interfolded sheets are directly transferred from the lower carriage, first count finger and second count finger to the downstream component.

In a particular embodiment, the downstream component is a conveyor.

In a particular embodiment, the first count finger is mounted to a first carriage, the second count finger is mounted to a second carriage, the third count finger is mounted to a third carriage and the fourth count finger is mounted to a fourth carriage. The apparatus further includes a sixth carriage. The lower carriage, first, second, third, fourth and sixth carriages all being independently moveable.

In a particular embodiment, the continuous stream of interfolded sheets defines a center line. A first three of the first, second, third, fourth, sixth and lower carriages are located on a first side of the centerline. A second three of the first, second, third, fourth, sixth and lower carriages being located on a second side of the centerline.

In a particular embodiment, the first three includes the first carriage, the third carriage and the sixth carriage and the second three includes the second carriage the fourth carriage and the lower carriage.

In a particular embodiment, each of the first, second, third, fourth, sixth and lower carriages is movable parallel to the center line as well as into and out of the continuous stream of interfolded sheets.

In a particular embodiment, the controller is configured to switch the order of insertion for the first count finger and the second count finger such that the first count finger acts as the second count finger but from the opposite side of the center line. The controller is configured to switch the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line. The controller is configured to switch the order of insertion of the lower carriage and the sixth carriage such that the sixth carriage acts as the lower carriage.

In another embodiment, a separating and interfolding apparatus includes a pair of counter rotating folding rolls and at least one count finger. The counter rotating folding rolls rotate about axis of rotation. The at least one count finger pivots between a retracted state and an extended state about a count finger axis of rotation. The count finger axis of rotation is positioned laterally outward from the axis of rotation of the folding rolls such that the count finger axis of rotation is not positioned between the folding roll axis of rotation. This arrangement improves the direction of travel of the count finger to reduce the detrimental effect of impact of the count finger on the building stack of interfolded sheets. More particularly, it provides a more axially directed motion for the finger rather than a radially directed motion.

In a particular embodiment, a tip of the count finger moves in an axial direction parallel to a stream of interfolded sheets exiting the counter rotating folding rolls a further distance than the tip of the count finger moves horizontally perpendicular to the stream of interfolded sheets.

In a particular embodiment, the axial motion is at least 30 percent greater than the horizontal motion.

In a particular embodiment, the axial motion is at least 60 percent greater than the horizontal motion.

In another embodiment, a separator arrangement for separating stacks of interfolded sheets from a stream of interfolded sheets is provided. The stream of interfolded sheets forms a center line. The separator arrangement includes a lower carriage, a first carriage, a second carriage, a third carriage, a fourth carriage, and a sixth carriage. The first, third and lower carriage are located on a first side of the center line, the second, fourth and sixth carriage are located on a second side of the center line opposite the first side. A first count finger is mounted to the first carriage. A second count finger is mounted to the second carriage. A third count finger is mounted to the third carriage. A fourth count finger is mounted to the fourth carriage. A controller is configured to control the first, second, third, fourth, sixth and lower carriages independently to insert the first, second, third, fourth count fingers, the lower carriage, and the sixth carriage into openings formed in the stream of interfolded sheets.

In a particular embodiment, the controller is configured to insert the first count finger, second count finger, third count finger, fourth count finger, lower carriage and sixth carriage into the stream of interfolded sheets based on a first count insertion sequence for a first interfolded product and based on a second count insertion sequence for a second interfolded product different than the first interfolded product.

In a particular embodiment, the controller is configured to operate in the first count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets of the first product have only a single panel interfolded. The controller is configured to operate in the second count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets of the second product have more than one panel interfolded. When operating in the first count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into first, second, third and fourth openings that are consecutive openings. When operating in the second count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings, respectively, with the first and second openings being adjacent one another, the third and fourth openings being adjacent one another and the second and third openings being separated from one another by an opening other than the first, second, third and fourth openings.

In a particular embodiment, the controller is configured to switch between first and second count insertion sequences. Switching between the first and second count insertion sequences switches the order of insertion for the first count finger and the second count finger such that the first count finger acts as the second count finger but from the opposite side of the center line. Switching between the first and second count insertion sequences switches the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line. Switching between the first and second count insertion sequences switches the order of insertion of the lower carriage and the sixth carriage such that the sixth carriage acts as the lower carriage.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:

FIGS. 1-12 illustrate a system and method for separating a continuous stream of interfolded sheets into a stack of interfolded sheets.

FIGS. 13 and 14 illustrate alternative features that may be incorporated into the system and method illustrated in FIGS. 1-12.

FIGS. 15A-15C illustrate different interfold patterns that could be separated using embodiments of the invention.

FIG. 16 illustrates separation of one of the patterns of interfolded sheets in FIG. 15.

FIG. 17 compares count finger motion profile of an improved separator arrangement with the motion profile of a count finger of a prior separator arrangement.

FIG. 18 illustrates a stack of sheets formed using a count finger motion profile according to an embodiment of the invention.

FIG. 19 illustrates a stack of sheets formed using a count finger motion profile of prior count finger configurations.

While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a portion of a sheet interfolder and separation arrangement 100. The sheet interfolder and separation arrangement receives a plurality of sheet like product, such as napkins or facial tissues, and interfolds the sheets to form a continuous stream 102 of interfolded sheets. Also, the sheet interfolder and separation arrangement 100 is configured to separate the continuous stream 102 of interfolded sheets into individual stacks 104 of sheets (see e.g. FIG. 7) which will ultimately be formed into packs for shipment to customers.

The sheet interfolder and separation arrangement 100 includes an interfolder arrangement 106 configured to receive the sheets and interfold the sheets to form the continuous stream 102 of interfolded sheets. The interfolder arrangement 106 of the illustrated embodiment is formed by a pair of counter-rotating folding rolls 108, 110 which may include mechanical folding components such as tuckers and grippers or vacuum folding components or a combination thereof as are generally known in the art.

The counter-rotating folding rolls 108, 110 rotate about parallel axis 112, 114 and form a folding nip 116 therebetween.

The interfolder arrangement 106 may form various different configurations of interfolded sheets. Three such configurations are illustrated in FIG. 15.

Downstream from the interfolder arrangement is a separator arrangement 120 of the interfolder and separation arrangement 100. The separator arrangement 120 separates the continuous stream 102 of interfolded sheets into individual stacks 104. In the illustrated embodiment the separator arrangement 120 directly transfers the separated stacks 104 to a downstream component. In this embodiment, the downstream component is a conveyor 122 illustrated by a broken dash-dot line in the relevant figures.

The separation arrangement 120 includes four count fingers 130, 132, 134, 136 for separating the continuous stream 102 of sheets into individual stacks 104 when a predetermined number of interfolded sheets have passed through the interfolder arrangement 106. The count fingers 130, 132, 134, 136 of a same side of the stream 102 of interfolded sheets are shown axially offset from one another. However, in operation, they would typically be aligned at a same axial location along the sheet flow path exiting the interfolder arrangement 106.

The count fingers 130, 132, 134, 136 pivot from a retracted state (see FIG. 1.) to an extended state (see e.g. FIGS. 2-5) about axis 138, 140. In the retracted state, the count fingers 130, 132, 134, 136 are generally out of and do not interfere with the stream 102 of interfolded sheets. In the illustrated embodiment, in the retracted state, the count fingers 130, 132, 134, 136 are recessed in grooves 142, 144 formed in the folding rolls 112, 114 and preferably radially inward of the outer surfaces of the folding rolls 112, 114 such that they do not interfere with the sheets exiting nip 116.

In the extended state (see e.g. FIGS. 2-5), the count fingers 130, 132, 134, 136 are pivoted out of the grooves 142, 144 and into the continuous stream of sheets 102 and particularly into openings (e.g. opening 150 in FIG. 1) in the stream of sheets formed between adjacent panels of the sheets within the stream 102 of sheets.

The separation arrangement 120 includes a carriage 152 upon which the stream 102 of sheets builds prior to separation of stacks. The carriage 152 moves axially along the sheet building path illustrated by arrow 154 so as to attempt to maintain a constant back pressure during the sheet interfolding process.

In FIG. 1, the four count fingers 130, 132, 134, 136 are staged in folding roll grooves 142, 144 while product (e.g. interfolded sheets) is building on lower carriage 152.

In FIG. 2, sufficient product has passed through the interfolding rolls 108, 110 such that stack separation can be initiated. First count finger 130 inserts into the stream 102 of interfolded sheets and particularly into opening 150. The count finger 130 pivots about axis 138 from the retracted state into the extended state and is now out of groove 144. The remainder of the count fingers 132, 134, 136 remain retracted and staged within grooves 142, 144. Product continues to build on lower carriage 152.

In FIG. 3, a second count finger 132 is inserted into stream 102 and particularly into opening 154 which is upstream of opening 150 and adjacent opening 150. Product is building on lower carriage 152. The count finger 132 pivots about axis 140 from the retracted state into the extended state and is now out of groove 142. The remainder of the count fingers 134, 136 remain retracted and staged within grooves 142, 144. Product continues to build on lower carriage 152.

In FIG. 4, a third count finger 134 is inserted into stream 102 and particularly into opening 156 which is upstream of opening 154 and adjacent opening 154. Product is building on lower carriage 152. The count finger 134 pivots about axis 138 from the retracted state into the extended state and is now out of groove 144. The remaining count finger 136 remains retracted and staged within grooves 142. Product continues to build on lower carriage 152. Count fingers 130, 132 begin to move axially downstream away from the interfolder arrangement 106 so as to avoid creating too much back pressure on the interfolder arrangement 106. This can be illustrated by the rotational axis 138A, 140A of these count fingers 130, 132 being moved axially downstream.

In FIG. 5, a fourth count finger 136 is inserted into stream 102 and particularly into opening 145 which is upstream of opening 154 and adjacent opening 154. Product is building on lower carriage 152. The count finger 136 pivots about axis 140B from the retracted state into the extended state and is now out of groove 142. Count fingers 130, 132, 134 are moving axially downstream away from the interfolder arrangement 106 so as to avoid creating too much back pressure on the interfolder arrangement. This can be illustrated by the rotational axis 138A, 140A, 138B of these count fingers 130, 132, 134 being moved axially downstream.

In FIG. 6, all count fingers 130, 132, 134, 136 are inserted into corresponding openings in the stream 102 of sheets. Product is building on top of the count fingers 130, 132, 134, 136, and particularly count fingers 134, 136, until there is sufficient product, e.g. pressure, above the count fingers to initiate a separation. The count fingers 130, 132, 134, 136 move axially downstream away from the interfolder arrangement 106. In this embodiment, the count fingers 130, 132, 134, 136 are moving vertically downward and generally parallel to gravity.

In FIG. 7, the first and second count fingers 130 and 132 together with the lower carriage 152 strip the counted stack 104 down toward the product conveyor 122 by accelerating away from count fingers 134, 136 and the interfolder arrangement 106. The continuous stream 102 continues to build on the third and fourth count fingers 134, 136. As can be seen, a panel of an upstream sheet controlled by upstream count fingers 134, 136 is pulled from opening 154 formed by adjacent panels of a downstream sheet controlled by count fingers 130, 132.

As such, the pack 104 is actively separated from the stream 102 while all sheets are controlled by the count fingers. The separation is not reliant on gravity. Further, the insertion of the count fingers occurs at openings that are created by the interfolder arrangement 106, again, without relying on gravity.

In FIG. 8, an air blast 162 near the conveyor 122 tucks the bottom panel of the counted stack 104 under the lower carriage 152 as the first and second count fingers 130, 132 together with the lower carriage 152 deliver the pack to the conveyor 122. Continuous stream 102 continues to build on count fingers 134, 136.

In FIG. 9, the first and second count fingers 130, 132 and the lower carriage 152 retract to place the counted stack 104 on the product conveyor 122. Continuous stream 102 continues to build on count fingers 134, 136.

In FIG. 10, the first and second count fingers 130, 132 return to the home position within grooves 142, 144 and in a retracted state. The lower carriage 152 moves up to receive the building continuous stream 102 of sheets from the second and third count fingers 134, 136 and is inserted into opening 156 occupied by third count finger 134. The stack 104 on the conveyor 122 is being conveyed out of the separator arrangement 120.

In FIG. 11, the third and fourth count fingers 134, 136 retract to complete the handoff of the building stream 102 to the lower carriage 152.

In FIG. 12, the separator arrangement 120 has returned to its original state of FIG. 1. Here, the product is building on the lower carriage 152 and the four count fingers 130, 132, 134, 136 are retracted and ready for forming the next count, i.e. stack.

FIG. 13 illustrates a variation of the process, and particularly, the portion of the process of FIG. 7. FIG. 13 illustrates the addition of refold fingers 170, 172 mounted to the carriages that carry the first and second count fingers 130, 132. The refold fingers 170, 172 actively refold the two panels remaining on the top of each counted stack 104 after separation.

FIG. 14 illustrates a variation of the process, and particularly, the portion of the process of FIGS. 7 and 13. In this embodiment, the system includes the addition of a fold finger 176 used to create a half-panel known as a starter sheet on the bottom of each counted stack 104. This additional fold finger 176 could be mounted to the second count finger carriage or it could be a sixth independently mounted and driven carriage similar to the four count carriages and the lower carriage. An air blast 180 folds the half-panel around the additional fold finger 174.

FIGS. 15A-15C illustrate three common interfolded sheet overlap patterns and the count finger placements for proper separation using this method. The far left is the known as the singlefold overlap. The middle is known as three-panel multifold interfold overlap. The far right is known as four-panel multifold with 50% overlap. In both the singlefold and three-panel multifold the four count fingers are inserted into four consecutive panel openings which requires alternating sides with each count finger. The four-panel multifold with 50% overlap cannot be separated in the same way. This method provides the flexibility to alter the count insertion sequence to separate different products.

FIG. 16 illustrates the count finger and resulting panel arrangement of separating the four-panel 50% overlap. Similar to FIG. 14, this method uses refold fingers 170, 172 mounted to the first and second count finger carriages and an additional fold finger 176 below each counted pack. Again, the lower fold finger 176 could be mounted directly to a count finger carriage or be an independent carriage.

The count fingers 130, 132, 134, 136 and the lower carriage 152 are mounted to carriages for independent motion both axially parallel to the flow sheets as well as perpendicular to the flow of sheets, i.e. into and out of the stream. As such, the motion of each component can be individually controlled. As such, the count fingers can be moved laterally toward the center line of the stream of sheets or laterally away from the center line of the stream of sheets each independently. The count fingers can also be moved axially parallel to the center line of the stream of sheets, i.e. toward or away from the interfolder arrangement 106, independently. The count fingers can also each be independently actuated for rotation about corresponding axis 138, 140.

FIG. 14 illustrates a controller 190 which can operably control actuation of the various components including the pivoting motion of count fingers 130, 132, 134, 136 as well as the axial and transverse positioning into and along the sheet stream 102. The motion of the refold and fold fingers and lower carriage can also be controlled by the controller 190. Because the carriages are independently controlled, the controller 190 of the system in FIG. 14 is not tied to forming separations with the lower carriage entering from the same side. Instead, the system is effectively ambidextrous such that the first and third count fingers can switch responsibilities and order of insertion with the second and fourth count fingers and the lower carriage and additional fold finger scan switch responsibilities and order of insertion.

By using the illustrate apparatus and methods, the separation of a stack 104 from the stream 102 of sheets is fully controlled by the separator arrangement 120 and particularly count fingers 130, 132, 134, 136 such that the formation of openings for insertion of separator fingers or other fingers does not rely on gravity. As such, improved separation and stack formation can be accomplished by the instant invention. More particularly, the top sheet of a stack to be formed is controlled by a count finger during the entire stripping or separation process rather than being inserted after the stack has been partially transitioned away from the continuous stream 102 of sheets and into an opening formed, at least in part, by gravity acting on the sheets forming the stack.

It has been determined that a substantially vertical motion of the count fingers 130, 132, 134, 136 as they pivot from the retracted state to the extended state and out of the corresponding grooves 142, 144 can improve pack consistency and appearance. To improve the vertical motion of the count fingers 130, 132, 134, 136, the axis 138, 140 are preferably spaced radially outward from the central axis 112, 114 of the folding rolls 108, 110 while transitioning the count fingers from the retracted to the extended states. It is also desired to have the axis 138, 140 above or proximate the panels of the sheets with in continuous stream 102 upon which the count fingers will press when inserted into the stream 102 after being transitioned into the extended state.

FIG. 17 illustrates a motion profile, illustrated by arc 192, on the left side of the illustration with improved count fingers having the axis of rotation laterally outward from the axis of rotation of the folding rolls as well as with an elevated position. The count finger 200 on the right has an increased horizontal, i.e. transverse or lateral, vector component as compared to the horizontal component of profile 192. The profile of count finger 200 is illustrated by motion profile arc 202.

FIG. 18 illustrates a stack formed using a motion profile similar to arc 192 while FIG. 19 illustrates a stack formed using a motion profile similar to arc 202.

FIG. 17 illustrates a packer finger used to pack the sheets in the continuous stream of sheets. It is desired to transition the pivot axis for the count fingers as close as possible to the axis of rotation of the packer finger pivot axis.

More particularly, motion profile 192 has a greater amount of axial motion parallel to the sheet stream, i.e. axis 210, than the amount of motion perpendicular to axis 210. Preferably, axial motion parallel to axis 210 is at least 20 percent greater than the horizontal motion towards axis 210, more preferably at least 30 percent greater, more preferably 50 percent greater, more preferably at least 60 percent greater. In some embodiments, the axial motion parallel to axis 210 may be in excess of 70 percent of the horizontal motion towards axis 210.

In one embodiment, the count fingers and carriage directly hand off the separated stack 104 to the downstream components, such as the conveyor 122 as discussed above.

All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. 

What is claimed is:
 1. A method of separating a stack of sheets from a continuous stream of interfolded sheets, the method including: supporting a continuously forming stream of interfolded sheets on a lower carriage; inserting first, second, third and fourth count fingers into separate openings of the stream of interfolded sheets upstream of the lower carriage; supporting a first upstream sheet forming a first bottom sheet of the continuous stream of interfolded sheets with the third count finger and controlling a first downstream sheet forming a top sheet of the stack with the second count finger; increasing the spacing between the third and second count finger to separate the first upstream sheet from the first downstream sheet.
 2. The method of claim 1, further comprising supporting a second bottom sheet forming a bottom of the stack with the lower carriage and securing the stack of sheets between the lower carriage and the first count finger and second count finger such that the stack of sheets is controlled by the lower carriage and the first count finger and second count finger.
 3. The method of claim 2, further comprising transporting the stack of sheets to a downstream component under the control of the first count finger, second count finger and the lower carriage and directly transferring the stack of sheets to the downstream component from the control of the first count finger, second count finger and lower carriage
 4. The method of claim 3, wherein the downstream component is a conveyor and transporting the stack of sheets includes directly transferring the stack of sheets to the conveyor from the control of the first count finger, second count finger and the lower carriage.
 5. The method of claim 3, wherein directly transferring the stack of sheets to the downstream component includes retracting the lower carriage, first count finger and second count finger transversely from the path.
 6. The method of claim 5, wherein the retraction of the lower carriage, first count finger and second count finger is perpendicular to the path.
 7. The method of claim 5, further including, after transferring the stack of sheets to the downstream component, inserting the lower carriage into the opening in which the third count finger is located and then retracting the third and fourth count fingers to hand off the continuously forming stream of interfolded sheets to the lower carriage.
 8. The method of claim 7, further including separating a second stack of sheets from the stream of interfolded sheets including: inserting first, second, third and fourth count fingers into a second set of separate openings of the stream of interfolded sheets upstream of the lower carriage; supporting a second upstream sheet forming a second bottom sheet of the continuous stream of interfolded sheets with the third count finger and controlling a second downstream sheet forming a top sheet of the second stack of sheets with the second count finger; increasing the spacing between the third and second count finger to separate the second upstream sheet from the second downstream sheet.
 9. The method of claim 1, wherein: the separate openings include first, second, third and fourth openings, the first and second openings are adjacent one another and the third and fourth openings are adjacent one another; the second and third openings are separated from one another by a fifth opening.
 10. The method of claim 1, wherein: inserting first, second, third and fourth count fingers into separate openings of the stream of interfolded sheets upstream of the lower carriage includes: inserting the first, second, third and fourth count fingers into four consecutive openings when adjacent sheets of the continuous stream of interfolded sheets have only a single panel interfolded; and inserting the first and second count fingers into consecutive openings and inserting the third and fourth count fingers into consecutive openings and wherein the second and third count fingers are inserted into openings that are separated from one another by an opening other than the first and fourth openings when adjacent sheets of the continuous stream of interfolded sheets have more than one panel interfolded.
 11. The method of claim 1, wherein the count fingers are mounted to independently movable carriages.
 12. The method of claim 1, wherein none of the openings in the continuous stream of interfolded sheets in which components are inserted are formed by gravity.
 13. The method of claim 1 further comprising switching the order of insertion of the first count finger and the second count finger such that the first count finger acts as the second count finger but from an opposite side of a center line of the continuous stream of interfolded sheets and switching the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line and switching the order of insertion of the lower carriage and a sixth carriage such that the sixth carriage acts as the lower carriage but from the opposite side of the center line.
 14. The method of claim 13, wherein the first count finger, third count finger and lower carriages are located on a same first side of the center line and the second count finger, fourth count finger and sixth carriages are located on same second side of the center line being opposite the first side.
 15. An apparatus for forming stacks of interfolded sheets from a stream of sheets, the apparatus comprising: an interfolder arrangement for interfolding the stream of sheets into a continuous stream of interfolded sheets; a separator arrangement including a lower carriage, first, second, third and fourth count fingers and a controller, the lower carriage being downstream from the interfolder arrangement and selectively supporting the continuous stream of interfolded sheets exiting the interfolder arrangement; the first, second, third and fourth count fingers being insertable into first, second, third and fourth openings of the continuous stream of interfolded sheets upstream of the lower carriage; the controller being configured to control the motion of the lower carriage, and first, second, third and fourth count fingers into the continuous stream of interfolded sheets, the controller configured to: control the third count finger to be inserted into the third opening formed by a first upstream sheet forming a first bottom sheet of the continuous stream of interfolded sheets to support the first bottom sheet of the continuous stream of interfolded sheets upstream of the lower carriage; control the second count finger to be inserted into the second opening formed by a first downstream sheet forming a top sheet of the stack to control a top of the stack upstream of the lower carriage; and control the second count finger, third count finger and lower carriage to increase the spacing between the third and second count finger to separate the first upstream sheet from the first downstream sheet.
 16. The apparatus of claim 15 wherein separator arrangement is configured to operate in a first count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets have only a single panel interfolded and in a second count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets have more than one panel interfolded; when operating in the first count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings such that the first, second, third and fourth count openings are consecutive openings; when operating in the second count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings, respectively, with the first and second openings being adjacent one another, the third and fourth openings being adjacent one another and the second and third openings being separated from one another by an opening other than the first, second, third and fourth openings.
 17. The apparatus of claim 15, further including a downstream component downstream from the interfolder arrangement, the separator arrangement transporting the stacks of interfolded sheets to the downstream component with the stack being controlled between the lower carriage and the first and second count fingers such that the stacks of interfolded sheets are directly transferred from the lower carriage, first count finger and second count finger to the downstream component.
 18. The apparatus of claim 17, wherein the downstream component is a conveyor.
 19. The apparatus of claim 15, wherein the first count finger is mounted to a first carriage, the second count finger is mounted to a second carriage, the third count finger is mounted to a third carriage and the fourth count finger is mounted to a fourth carriage; further including a sixth carriage, the lower carriage, first, second, third, fourth and sixth carriages all being independently moveable.
 20. The apparatus of claim 19, wherein: the continuous stream of interfolded sheets defines a center line; a first three of the first, second, third, fourth, sixth and lower carriages are located on a first side of the centerline; and a second three of the first, second, third, fourth, sixth and lower carriages being located on a second side of the centerline.
 21. The apparatus of claim 20, wherein the first three includes the first carriage, the third carriage and the sixth carriage and the second three includes the second carriage the fourth carriage and the lower carriage.
 22. The apparatus of claim 21, wherein each of the first, second, third, fourth, sixth and lower carriages is movable parallel to the center line as well as into and out of the continuous stream of interfolded sheets.
 23. The apparatus of claim 21, wherein the controller is configured to switch the order of insertion for the first count finger and the second count finger such that the first count finger acts as the second count finger but from the opposite side of the center line and the controller is configured to switch the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line and the controller is configured to switch the order of insertion of the lower carriage and the sixth carriage such that the sixth carriage acts as the lower carriage.
 24. A separating and interfolding apparatus comprising: a pair of counter rotating folding rolls rotating about axis of rotation; at least one count finger pivoting between a retracted state and an extended state about a count finger axis of rotation, the count finger axis of rotation being positioned laterally outward from the axis of rotation of the folding rolls such that the count finger axis of rotation is not positioned between the folding roll axis of rotation.
 25. The separating and interfolding apparatus of claim 24, wherein a tip of the count finger moves in an axial direction parallel to a stream of interfolded sheets exiting the counter rotating folding rolls a further distance than the tip of the count finger moves horizontally perpendicular to the stream of interfolded sheets.
 26. The separating and interfolding apparatus of claim 25, wherein the axial motion is at least 30 percent greater than the horizontal motion.
 27. The separating and interfolding apparatus of claim 25, wherein the axial motion is at least 60 percent greater than the horizontal motion.
 28. A separator arrangement for separating stacks of interfolded sheets from a stream of interfolded sheets, the stream of interfolded sheets forming a center line, the separator arrangement comprising: a lower carriage, a first carriage, a second carriage, a third carriage, a fourth carriage, and a sixth carriage, the first, third and lower carriage being located on a first side of the center line, the second, fourth and sixth carriage being located on a second side of the center line opposite the first side; a first count finger mounted to the first carriage, a second count finger mounted to the second carriage, a third count finger mounted to the third carriage and a fourth count finger mounted to the fourth carriage; and a controller configured to control the first, second, third, fourth, sixth and lower carriages independently to insert the first, second, third, fourth count fingers, the lower carriage, and the sixth carriage into openings formed in the stream of interfolded sheets.
 29. The separator arrangement of claim 24, wherein the controller is configured to insert the first count finger, second count finger, third count finger, fourth count finger, lower carriage and sixth carriage into the stream of interfolded sheets based on a first count insertion sequence for a first interfolded product and based on a second count insertion sequence for a second interfolded product different than the first interfolded product.
 30. The separator arrangement of claim 25, wherein the controller is configured to operate in the first count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets of the first product have only a single panel interfolded and in the second count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets of the second product have more than one panel interfolded; when operating in the first count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into first, second, third and fourth openings that are consecutive openings; when operating in the second count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings, respectively, with the first and second openings being adjacent one another, the third and fourth openings being adjacent one another and the second and third openings being separated from one another by an opening other than the first, second, third and fourth openings.
 31. The separator arrangement of claim 24, wherein the controller is configured to switch between first and second count insertion sequences, wherein switching between the first and second count insertion sequences switches the order of insertion for the first count finger and the second count finger such that the first count finger acts as the second count finger but from the opposite side of the center line; wherein switching between the first and second count insertion sequences switches the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line; and wherein switching between the first and second count insertion sequences switches the order of insertion of the lower carriage and the sixth carriage such that the sixth carriage acts as the lower carriage. 